Complementing the topics of SenSys 2013, ENSSys will bring together researchers to systematically explore the challenges, issues and opportunities in the research, design, and engineering of energy-harvesting and energy-neutral sensing systems. These are a technological cornerstone for future applications in smart energy, future transportation, environmental monitoring and smart cities. Innovative solutions in on-board hardware for energy scavenging, energy adaptive algorithms, and power management policies are the ultimate frontiers, opening the door to unlimited and uninterrupted operation. High quality original technical articles from academia and industry are solicited, describing advances in sensing systems powered by energy harvesting, as well as those which describe practical deployments and implementation experiences. Attendees will benefit from ENSSys' co-location with SenSys 2013, widely regarded as one of the most prestigious conferences on sensor network research.